Been through this whole process, I can Co firm it will start even with the immobiliser disconnected Cps could be dodgy... I had to change the ecu, because we had swapped the Cps. A bad Cps will cause the same fault, check voltage to Cps is 12v even though some run 5v and do whatever rj says as eels. If buying another Cps, source a Meyle
crankshaft position sensor in this case. the cam sensor is only used as a cylinder 1 TDC reference so the ecu can run in full sequential injection mode. If you unplug it the engine will still run pretty well in batch fire mode. and yes you can tap ecu pin 7 to the main cranking live wire if you like, factory CE1 cranking live feed is taken from a spade on the C plug but when I make CE1 ABF looms I tap it to the main starter feed to make the loom simpler.
Yes crank angle postilion sensor as rj stated. If you've connected the vag port correctly, vagcom should find the immobiliser too. As the wires are frail and the connectors rare, i would by default remove the immobiliser to prevent any damage while tidying wires around fusebox. I have on several counts started the engine with the box removed and it starts and then shuts down in around 1 to 2 seconds after ignition. There is by default a weak spark at time of ignition, this shouldn't be factored into the diagnostics. Its rarely a coil and more often the Cps. Vagcom should find an immobiliser and report a crank potion sensor fault or intermittent fault if it is. If you can borrow a spare ecu, it would be worth trying to remove any doubt. From there I would check grounds and ensure battery can supply enough current and not riddled with internal resistance, if it did, you would not crank the starter anyway. rubjonny really knows his stuff, and the only thing you can't test is the Cps as it converts output to a square signal and replacing it is all you can do unless you own an oscilloscope and pass a magnet by it... , perhaps
with the crank sensor best way to check it is read the engine rpm measuring block in vagcom, then see if it goes up while cranking. depending on how the CPS fails it may not flag a code, and on some versions of the ABF ecu they flag a CPS fault if you scan the ECU with engine off even if the CPS is working OK
Awesome thanks guys. I think you're right, the problem is between the CPS, CPU and the ignition coil. I was just doing some diagnosis while you posted, results are as follows... *NB: LED tests were performed with ignition on, king lead off (to prevent accidental ignition) and hand cranking of engine. Test 1 - Crankshaft Position Sensor Wire 1a (Red/Yellow) - Continuity to ECU pin #68 is good, 12v with ignition on Wire 2a (Green/Black) - Continuity to ECU pin #67 is good, LED flicks on/off (square signal) with ignition on* and engine hand cranked, multimeter reads approx. 6.5v while cranking the engine via starter motor (multimeter isn't accurate enough to pick up much fluctuation) Wire 3a (Brown/Blue) - Continuity to earth is good, 0.97v with ignition on Test 2 - Ignition Coil / Amplifier Wire 1b (Brown) - Continuity to earth is good, 0.95v with ignition on = OK Wire 2b (Green/Red) - Continuity to ECU pin #8 is good, LED stays on & does not flick on/off (should be a square signal) with ignition on* and engine hand cranked Wire 3b (Black) - 12v with ignition on My wiring diagram says that the voltage from the CPS should only be 2v/1ms. Averaged out (for square signal) this should be well below 6.5v correct? Could a high voltage stop the signal being picked up by the ECU?
Seems like crank position sensor is good then, this is narrowing down... but dont let me sway your diagnosis...it will be rewarding once done
Apologies for the hijack but.. I think you may have just solved my emissions problem... Im pretty sure i may have spliced my sensor earths to ground on the cylinder head aswell as ECU... i am a little earth-happy lol could this explain general rough and rich running? I've got a spare mk3 loom here to start again with, now that i know what i'm doing lol
adding that extra earth had no effect on the running of my mates MK2, its still like that too as far as I'm aware 10 years or so on... when you check for continuity you put the meter to resistance/beep mode, the screen should show 1 and go to 0/beep when the probes are touched. Then you put 1 probe either end of the wire you want to test and you should see 0/beep on the display. if it sticks at 1 you have an open circuit, if it shows a number that is how much resistance you are seeing across the circuit. Sometimes seeing a number is good, for example when testing a heater you should see some resistance, the correct figure would need looking up to know if the heater is good or not though. Best bet for CPS fault finding plus most diagnostics on these is as already mentioned, plug VAGCOM in!
Message received loud and clear haha! I'm taking a break in Bali for a couple of weeks, will be getting stuck back in on my return To be continued...
Hey all, I finally managed to install VAGCOM, after ordering software from eBay, sourcing an old laptop, pulling my hair out as USB driver couldn't be found by Win7, sourcing another laptop, same problem, ordering another copy of the software, successfully installing and connecting... phew Below is what I got after connecting and running an AutoScan.. I'm new to VAGCOM, can I check sensor signals just by turning it over (i.e. without it idling)? I'm still leaning toward the crankshaft position sensor being the culprit, so want to try and measure the input.
First install these label files: http://www.clubgti.com/showthread.php?199583 that will make them easier to read
Awesome! Just run through the max 25 measuring groups allowed. I figured the first 7 from the text file, what are the other groups from 8 to 25? Below is my take on the results for groups 1-7. NB: Test performed with ignition on, not idling (I assume the 378 RPM shown in results is a minimum value) 001,0,Group Functions - OK 001,1,Idle_RPM,,Typ: 780...890 RPM 001,2,Coolant_Temp,,Typ: 85...105 C 001,3,Lambda_Volt,,Typ: 0...1.0 V 001,4,Adjust Cond,,Typ: 00000000 002,0,Group Functions - Potential Issues 002,1,Idle_RPM,,Typ: 780...890 RPM 002,2,Inj_Period,,Typ: 5...8 ms 53ms ?? 002,3,Bat_voltage,,Typ: 12...14.2 V Low batt - on trickle charge now 002,4,IAT,,Typ: 15...50 C It's cold tonight in Melbourne! 003,0,Idle Stabilization - OK 003,1,Idle_RPM,,Typ: 780...890 RPM 003,2,Engine_Load,,Typ: 23...36 003,3,TB_Angle,,Typ: 0 < (0...86) 003,4,Opening Value for ISV,,Typ: 7...25 No idle so assume this is fine 004,0,Operating Condition - Potential Issues 004,1,Idle_RPM,,Typ: 780...890 RPM 004,2,Engine_Load,,Typ: 23...36 004,3,[N/A], Timing BTDC? 255 ?? 004,4,Operating Cond 00100000 - This corresponds to 'Part Load', but engine isn't running... 005,0,Charcoal Valve - OK 005,1,Idle_RPM,,Typ: 780...890 RPM 005,2,Soleniod,Duty Ratio,(N80), 0...23 005,3,Fuel Consumption,mS 005,4,Operating Cond?,Lambda 00000000? 006,0,Fuel Trim Learned Values - OK 006,1,Lambda_Int,If 0 ,or 255 006,2,Lambda_Int1,0...70 ,or 144...255 006,3,Learned Value for,idle, 8...48 006,4,TB_Pot_Closed_Learned,Value,24...98 007,0,Adaptation Values - OK 007,1,ISV,,Typ: 20...50 007,2,Mixture,,Typ: 82...174 007,3,Lambda,Regulation Freq, 0 respectively 15 007,4,MAP,,Typ: 70...90 8 - 9? 10 - 12? 13 - 15? 16 - 18? 19 - 21? 22 - 24? 25?
I'm guessing this is what I'm after! http://www.ross-tech.com/vag-com/m_blocks/ Specifically the Engine Speed section: http://www.ross-tech.com/vag-com/m_blocks/050-059.html It says approx. 1999 onward, does this stand for a 1997 ABF?
you're supposed to copy and paste all of that into 2 label files then copy them into the vagcom label folder, then it will show all the text for you under the blocks in vagcom main thing is does the throttle body angle change as you would expect when you work the throttle, and when you crank it over does the engine rpm go up?
I had already copied the label files, after a bit of head scratching I realised they'd saved as *.lbl.txt not *.lbl .. oops! The labels only apply from 001 to 007. Is this correct? The throttle body angle changes from 0.0% to a max of 32.0% when I plant the pedal. The engine RPM goes from 378RPM (apparent baseline) to 459RPM when I crank it over. I'm not getting any error codes (after clearing an immob code that hasn't returned). If I unplug the CSP and turned it over, I don't getting an error code. Combined with the above, this implies that the ECU might not be getting all the appropriate data / isn't reading all sensors... How many measuring block groups should I be able to read in '01. Engine'? I can only read 001 to 025, if I try to scroll up further or enter a number above 025, I get an VCDS error message/window.
